FAQ: Kiwi Kapers, I wonder what is the median weight of kiwis? How should I encourage my students to write conclusions when making an inference?

My random sample of 30 kiwis has produced an informal confidence interval for the population median weight of kiwis of (_______ , _______ ) kg.
Based on this confidence interval I am pretty sure the population median weight of kiwis is somewhere between ________ kg and __________ kg.

I know that if I take another random sample I will get a different sample median so I cannot make a reliable estimate of the population median based the sample median alone. Therefore I used an interval centered on the sample median to capture a range of plausible values for the population median.

I know that sample medians and IQR’s vary from sample to sample. This means another random sample of 30 kiwi weights would almost certainly give a different interval. However the process I used to find the interval includes the population median weight about 90% of the time.

  • (Last updated: 13/07/17. Added: 19/02/13)